UWB-based Physical Layer Key Sharing for BAN Devices

The increasing commercial viability of body area network (BAN) devices has expanded their applications beyond smartwatches and smartphones to include wearables for industrial safety, healthcare monitoring, and augmented reality systems. Secure communication between these devices remains a challenge, as traditional cryptographic key exchange protocols impose significant computational and power constraints. Physically Derived Symmetric Key (PDSK) generation offers a lightweight alternative by leveraging the shared wireless channel characteristics to establish encryption keys without prior trust. Recent studies have demonstrated the effectiveness of PDSK in ultra-wideband (UWB) systems, as UWB's high-resolution channel measurements capture high-entropy yet highly correlated signal variations at different devices. In this work, we evaluate the feasibility of UWB-based PDSK in BAN wearable devices. Our results show that secret keys can be reliably generated, achieving a bit agreement rate (BAR) of 84.14% and a key success rate (KSR) of 92.7% while generating 240-bit keys in 0.35s. We further analyse key generation performance across different wearable placements and movement conditions, demonstrating that UWB-based PDSK is a viable and practical solution for secure communication in BAN applications. © 2025 IEEE.